Itching after Sarolaner (Simparica) in dogs

The FDA has received 1,104 reports of itching in dogs after Sarolaner. That is 6.6% of all reports for this medicine, compared with 4.3% across reports for all dog medicines, so it is reported unusually often with this medicine.

1,104Reports

30%Marked serious

22%Recovered

1.9%Died or euthanised

Same dayTypical onset

How soon it started

Same day

563 56%

1–2 days

233 23%

3–7 days

78 7.7%

1–4 weeks

66 6.5%

Over a month

74 7.3%

How the animals did

Recovered

241 22%

Recovered with lasting effects

2 0.2%

Still unwell when reported

495 45%

Died

8 0.7%

Euthanised

13 1.2%

Not known

345 31%

Problems reported at the same time

166 15%

156 14%

135 12%

117 11%

106 9.6%

92 8.3%

86 7.8%

64 5.8%

Age of the animals

Under 1 year

1–3 years

257

4–7 years

264

8–11 years

261

12+ years

167

About this medicine

Sarolaner kills fleas, ticks and some mites; monthly.

Products with this ingredient include Simparica. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

In 2018 the FDA alerted owners and vets that isoxazoline products have been associated with neurologic reactions such as muscle tremors, wobbliness (ataxia) and seizures, including in animals with no history of them.

Questions owners ask

Can Sarolaner cause itching in dogs?: 1,104 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
How soon after a dose was it reported?: In half of the reports with dates, it started within the same day of the first dose.
What should I do?: Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).

Itching with similar medicines

Itching after Fluralaner (Bravecto) 2,940 reports · 4.3% of its reports
Itching after Afoxolaner (NexGard) 6,468 reports · 11% of its reports
Itching after Lotilaner (Credelio) 627 reports · 6.3% of its reports
Itching after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 495 reports · 5.3% of its reports
Itching after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 177 reports · 5.7% of its reports

All reported side effects of Sarolaner in dogs · Medicines most reported with itching